1,Made of ZrO2 and Y2O3; 2,Stain and Rust proof; 3.Easy to clean; 4.Ultra-sharp ... tech Zirconia crafted, high-density, high hardness, never wear.2, Hardness (HRA90) is next to diamond, and abrasion ... extremely-hard blade, nearly as hard as diamonds.2, Sharpness: The materials that make up a ceramic ... wooden or plastic chopping block at the same time.2,Please avoid chopping or prizing with ceramic tips , ...